A global analysis of tonal noise in flows around aerofoils

Miguel Fosas De Pando, Peterâ J. Schmid, Denis Sipp

Research output: Contribution to journalArticlepeer-review

51 Scopus citations

Abstract

The generation of discrete acoustic tones in the compressible flow around an aerofoil is addressed in this work by means of nonlinear numerical simulations and global stability analyses. The nonlinear simulations confirm the appearance of discrete tones in the acoustic spectrum and, for the chosen flow case, the global stability analyses of the mean-flow dynamics reveal that the linearized operator is stable. However, the flow response to incoming disturbances exhibits important transient growth effects that culminate in the onset of aeroacoustic feedback loops, involving instability processes on the suction- and pressure-surface boundary layers together with their cross-interaction by acoustic radiation at the trailing edge. The features of the aeroacoustic feedback loops and the appearance of discrete tones are then related to the features of the least-stable modes in the global spectrum: the spatial structure of the direct modes displays the coupled dynamics of hydrodynamic instabilities on the suction surface and in the near wake. Finally, different families of global modes will be identified and the dynamics that they represent will be discussed. © 2014 Cambridge University Press.
Original languageEnglish (US)
Pages (from-to)5-38
Number of pages34
JournalJournal of Fluid Mechanics
Volume754
DOIs
StatePublished - Jan 1 2014
Externally publishedYes

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'A global analysis of tonal noise in flows around aerofoils'. Together they form a unique fingerprint.

Cite this